5.1.1 Download Failed; Can't Retry

So here's the deal. Last night I downloaded 5.1.1 on my Nexus 9. However, it appears it didn't actually download. So I went to my System Update setting today, and I saw this screen.
Here's the funny business. When I click "Retry Download", nothing happens. The button highlights, signifying that it has been clicked, but it stays on that screen. What on earth?
I've already restarted and reset my tablet (not factory. I did the power + volume thing) and still nada. How do I fix this little bug?

So here's the deal. Last night I downloaded 5.1.1 on my Nexus 9. However, it appears it didn't actually download. So I went to my System Update setting today, and I saw this screen.
Here's the funny business. When I click "Retry Download", nothing happens. The button highlights, signifying that it has been clicked, but it stays on that screen. What on earth?
I've already restarted and reset my tablet (not factory. I did the power + volume thing) and still nada. How do I fix this little bug?